"H. S. Teoh" <hst...@quickfur.ath.cx> writes: > I have a Scheme function that returns a music expression. Unfortunately, > the expression returned depends on the properties of the context it's > evaluated in. I.e., based on the current setting of > Staff.dynamicAbsoluteVolumeFunction it will return a different number of > events in the music expression. > > Is this possible?
\applyContext works at the process-music stage. That's actually a bit late to generate stream events. > The background of this is that I'm writing a Scheme function that > generates single-note crescendos by emitting a series of \set > Staff.midiExpression = ... events. Oh, but that's perfectly manageable with \applyContext. Don't generate any events, just call ly:context-set-property! directly. If you don't want to find Staff yourself, you can just write \context Staff \applyContext (lambda ... and then the context passed to the applyContext function will already be a Staff context. > Currently I've written a Scheme function that's able to generate these > events; however, it requires me to specify numerical starting / ending > values for midiExpression. I'd like to be able to specify dynamics > instead of numerical values, and have the Scheme function > automatically look up the numerical values based on the current volume > function defined for the Staff. > > However, so far I haven't been able to figure out how to read the > Staff properties except using \applyContext with a lambda, and AFAICT > it's not possible to return a music expression from this lambda? So far it does not sound like you want anything returned rather than setting some properties. -- David Kastrup _______________________________________________ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
